Objective: To isolate a-mangostin(AMG) from the peels of mangosteen(Garcinia mangostana L.), grown in Vietnam, and to investigate antibiofilm activity of this compound against three Staphylococcus aureus(S. aureus) st...Objective: To isolate a-mangostin(AMG) from the peels of mangosteen(Garcinia mangostana L.), grown in Vietnam, and to investigate antibiofilm activity of this compound against three Staphylococcus aureus(S. aureus) strains, one of which was methicillin-resistant S. aureus(MRSA) and the other two strains were methicillinsensitive S. aureus(MSSA).Methods: AMG in n-hexane fraction was isolated on a silica gel column and chemically analyzed by HPLC and NMR. The antibiofilm activity of this compound was investigated by using a 96-well plate model for the formation of biofilms. Biofilm biomass was quantified using crystal violet. The viability of cells was observed under confocal microscopy using LIVE/DEAD Bac Light stains. Biofilm composition was determined using specific chemical and enzyme tests for polysaccharide, protein and DNA. Membranedamaging activity was assayed by measuring the hemolysis of human red blood cells in presence of AMG.Results: The results indicated that the isolated AMG, with a purity that exceeded 98%,had minimal inhibitory concentrations in the range of 4.6–9.2 mmol/L for the three strains tested. Interestingly, the MSSA strains were more sensitive to AMG than the MRSA strain. Minimal bactericidal concentrations were 2-fold higher than the minimal inhibitory concentration values for the three strains, indicating that AMG was a bactericidal compound. AMG also prevented biofilm formation effectively, albeit that again the MRSA strain was the most resistant. Interestingly, biofilms of the MRSA strain contained protein as a main component of the extracellular matrix, whereas this was polysaccharide in the MSSA strains. This might relate to the resistance of the MRSA 252 strain to AMG.Assays using human red blood cells indicated that AMG caused significant membrane damage with 50% of cell lysis occurred at concentration of about 36 mmol/L.Conclusions: Our results provide evidence that the isolated AMG has inhibitory activity against biofilm formation by S. aureus, including MRSA. Thus, isolated AMG proposes a high potential to develop a novel phytopharmaceutical for the treatment of MRSA.展开更多
Background： Although increasing parity increased the risk of pregnancy complications and despite of Vietnam’s family planning policy of two-child, the percent of women having three or more children has tended fo...Background： Although increasing parity increased the risk of pregnancy complications and despite of Vietnam’s family planning policy of two-child, the percent of women having three or more children has tended for five years. Objectives： （1） Find out the prevalence of parity ≥ 3 and their reasons at Haiphong Hospital of Obstetrics and Gynecology in 2016; （2） Describe the methods of labor and its adverse outcomes. Materials and methods： A cross-sectional in 485 women had delivered three or more infants at Haiphong Hospital of Obstetrics and Gynecology from June to August, 2016. Results： The prevalence of parity ≥ 3 is 11.9%, no relation to geopraphy, education and career. The main reasons are unplanned pregnancy and desire to have a baby boy. The sex ratio at birth is 162. The proportion of cesarean delivery is 53.4%, in which is due to an old C-section. Conclusion： serious gender is imbalance among women having three or more baby （162 baby boys per hundred baby girls）.展开更多
基金Supported by the TWAS research grant 14-062 RG/BIO/AS_GNAFOSTED grant 106-NN.02–2016.19National Research Council of Thailand(NRCT)and Center of Excellence for Innovation in Chemistry(PERCH-CIC)
文摘Objective: To isolate a-mangostin(AMG) from the peels of mangosteen(Garcinia mangostana L.), grown in Vietnam, and to investigate antibiofilm activity of this compound against three Staphylococcus aureus(S. aureus) strains, one of which was methicillin-resistant S. aureus(MRSA) and the other two strains were methicillinsensitive S. aureus(MSSA).Methods: AMG in n-hexane fraction was isolated on a silica gel column and chemically analyzed by HPLC and NMR. The antibiofilm activity of this compound was investigated by using a 96-well plate model for the formation of biofilms. Biofilm biomass was quantified using crystal violet. The viability of cells was observed under confocal microscopy using LIVE/DEAD Bac Light stains. Biofilm composition was determined using specific chemical and enzyme tests for polysaccharide, protein and DNA. Membranedamaging activity was assayed by measuring the hemolysis of human red blood cells in presence of AMG.Results: The results indicated that the isolated AMG, with a purity that exceeded 98%,had minimal inhibitory concentrations in the range of 4.6–9.2 mmol/L for the three strains tested. Interestingly, the MSSA strains were more sensitive to AMG than the MRSA strain. Minimal bactericidal concentrations were 2-fold higher than the minimal inhibitory concentration values for the three strains, indicating that AMG was a bactericidal compound. AMG also prevented biofilm formation effectively, albeit that again the MRSA strain was the most resistant. Interestingly, biofilms of the MRSA strain contained protein as a main component of the extracellular matrix, whereas this was polysaccharide in the MSSA strains. This might relate to the resistance of the MRSA 252 strain to AMG.Assays using human red blood cells indicated that AMG caused significant membrane damage with 50% of cell lysis occurred at concentration of about 36 mmol/L.Conclusions: Our results provide evidence that the isolated AMG has inhibitory activity against biofilm formation by S. aureus, including MRSA. Thus, isolated AMG proposes a high potential to develop a novel phytopharmaceutical for the treatment of MRSA.
文摘Background： Although increasing parity increased the risk of pregnancy complications and despite of Vietnam’s family planning policy of two-child, the percent of women having three or more children has tended for five years. Objectives： （1） Find out the prevalence of parity ≥ 3 and their reasons at Haiphong Hospital of Obstetrics and Gynecology in 2016; （2） Describe the methods of labor and its adverse outcomes. Materials and methods： A cross-sectional in 485 women had delivered three or more infants at Haiphong Hospital of Obstetrics and Gynecology from June to August, 2016. Results： The prevalence of parity ≥ 3 is 11.9%, no relation to geopraphy, education and career. The main reasons are unplanned pregnancy and desire to have a baby boy. The sex ratio at birth is 162. The proportion of cesarean delivery is 53.4%, in which is due to an old C-section. Conclusion： serious gender is imbalance among women having three or more baby （162 baby boys per hundred baby girls）.
